Chapter 6 Integumentary System – Part 1

Vocabulary flashcards covering key terms from Chapter 6: Integumentary System, Part 1.

Integumentary system

The skin and its accessory structures (hair, nails, glands, sensory receptors); the largest organ by weight.

Skin (cutaneous membrane)

The organ that makes up the integumentary system; also called the cutaneous membrane.

Epidermis

Outer layer of skin composed of stratified squamous epithelium; avascular and nourished by dermal vessels.

Dermis

Inner, thicker layer of skin made of connective tissue with collagenous and elastic fibers; houses glands, hair follicles, nerves, and blood vessels.

Hypodermis (subcutaneous layer)

Beneath the dermis; insulating layer of areolar and adipose tissue; not considered part of the skin.

Basement membrane

Layer between the epidermis and dermis that anchors epidermis to the underlying tissue.

Stratum basale

Deepest epidermal layer; a single row of dividing cuboidal/columnar cells; includes melanocytes.

Stratum spinosum

Layer beneath granulosum; many cell layers with developing keratin; cells begin flattening.

Stratum granulosum

Three to five layers of flattened granular cells containing keratin and shriveled nuclei.

Stratum lucidum

Clear epidermal sublayer present only in thick skin (soles and palms); between corneum and granulosum.

Stratum corneum

Outermost epidermal layer; many layers of keratinized, dead, non-nucleated cells; provides protection and water resistance.

Keratinization

Process of hardening, dehydration, and keratin accumulation as epidermal cells migrate outward.

Keratin

Tough, fibrous, waterproof protein produced by epidermal cells.

Desmosomes

Cell junctions that hold keratinocytes together in the epidermis.

Melanocytes

Cells in the stratum basale that produce melanin and distribute it to keratinocytes.

Melanin

Pigment that gives skin its color and protects against UV radiation.

Eumelanin

Brownish-black form of melanin contributing to darker skin tones.

Pheomelanin

Reddish-yellow form of melanin found in some areas.

Albinism

Inherited mutation in melanin genes resulting in lack of melanin.

Dendritic (Langerhans) cells

Phagocytic cells in the stratum spinosum that protect against infection.

Tactile (Merkel) cells

Sensory cells in the stratum basale that function with nerve endings for light touch.

Dermal papillae

Projections of the dermis between epidermal ridges; form fingerprints; increase surface area.

Meissner’s (tactile) corpuscles

Receptors in the dermal papillae that detect light touch.

Pacinian (Lamellated) corpuscles

Sensory receptors in the dermis that detect deep pressure and vibration.

Papillary layer

Superficial dermal layer of areolar connective tissue; contains dermal papillae and helps form fingerprints.

Reticular layer

Deeper, thicker dermal layer of dense irregular connective tissue; houses hair follicles, glands, nerves.

Epidermis lacks blood vessels

The epidermis is avascular; nutrients diffuse from the dermis.

Thick skin

Areas with stratum lucidum (palms and soles); thicker epidermis overall.

Hair follicles

Structures within the dermis that produce hair.

Sweat glands

Glands in the dermis that produce sweat for thermoregulation and excretion.

Sebaceous glands

Glands in the dermis that secrete sebum to lubricate hair and skin.

Melanin distribution to keratinocytes

Melanin is transferred from melanocytes to keratinocytes to protect skin cells from UV damage.

Skin color factors: carotene

Orange-yellow pigment from diet; accumulates in adipose tissue and stratum corneum.

Skin color factors: oxygenation and vasculature

Color changes due to blood oxygen levels and vessel dilation/constriction (pink, cyanosis).

Jaundice

Yellow discoloration from bile pigment; a physiological factor affecting skin color.

Cyanosis

Bluish skin tint due to low blood oxygen.

Indoor tanning

Exposure to UV radiation to darken skin via increased melanin; associated with higher cancer risk.

Basal cell carcinoma

Most common skin cancer arising from epithelial cells in skin.

Squamous cell carcinoma

Skin cancer arising from squamous epithelia; can metastasize if untreated.

Melanoma

Most deadly but least common skin cancer; arises from melanocytes and causes majority of skin cancer deaths.